Segfault when requesting thumbnails on closing with a non-empty clipboard

While testing Tumbler yesterday, I had a crash of Thunar 4.17.7 that I can't reproduce, but here's the backtrace:

Core was generated by `Thunar --daemon'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x000055783ae67e92 in thunar_icon_factory_get_show_thumbnail (factory=0x0, file=0x7f8c5001fd10) at thunar-icon-factory.c:819
819	thunar-icon-factory.c: Aucun fichier ou dossier de ce type.
[Current thread is 1 (Thread 0x7f8c93f689c0 (LWP 1602))]
(gdb) bt
#0  0x000055783ae67e92 in thunar_icon_factory_get_show_thumbnail (factory=0x0, file=0x7f8c5001fd10) at thunar-icon-factory.c:819
#1  0x000055783ae972f3 in thunar_standard_view_request_thumbnails_real (standard_view=0x55783bbc5e80, lazy_request=1) at thunar-standard-view.c:3580
#2  0x00007f8c979bdad4 in  () at /usr/lib/libglib-2.0.so.0
#3  0x00007f8c979bd435 in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#4  0x00007f8c97a117b9 in  () at /usr/lib/libglib-2.0.so.0
#5  0x00007f8c979bcab3 in g_main_loop_run () at /usr/lib/libglib-2.0.so.0
#6  0x00007f8c983378f0 in  () at /usr/lib/libgtk-3.so.0
#7  0x000055783ae51ab7 in thunar_clipboard_manager_dispose (object=0x7f8c6c010880) at thunar-clipboard-manager.c:199
#8  0x00007f8c97abe301 in g_object_unref () at /usr/lib/libgobject-2.0.so.0
#9  0x00007f8c97ab1d8f in g_closure_invoke () at /usr/lib/libgobject-2.0.so.0
#10 0x00007f8c97acd0ee in  () at /usr/lib/libgobject-2.0.so.0
#11 0x00007f8c97acedd9 in g_signal_emit_valist () at /usr/lib/libgobject-2.0.so.0
#12 0x00007f8c97acf330 in g_signal_emit () at /usr/lib/libgobject-2.0.so.0
#13 0x00007f8c982fba16 in gtk_widget_unrealize () at /usr/lib/libgtk-3.so.0
#14 0x00007f8c98306bb9 in  () at /usr/lib/libgtk-3.so.0
#15 0x00007f8c983125dd in  () at /usr/lib/libgtk-3.so.0
#16 0x00007f8c97ab3b8a in g_object_run_dispose () at /usr/lib/libgobject-2.0.so.0
#17 0x00007f8c981aea4b in gtk_main_do_event () at /usr/lib/libgtk-3.so.0
#18 0x00007f8c97f18643 in  () at /usr/lib/libgdk-3.so.0
#19 0x00007f8c97f63a24 in  () at /usr/lib/libgdk-3.so.0
#20 0x00007f8c979bd52c in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#21 0x00007f8c97a117b9 in  () at /usr/lib/libglib-2.0.so.0
#22 0x00007f8c979bac11 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#23 0x00007f8c97bd02fe in g_application_run () at /usr/lib/libgio-2.0.so.0
#24 0x000055783ae3f10e in main (argc=2, argv=0x7ffffc059b28) at main.c:86

It seems that standard_view->icon_factory can be null under certain circumstances (the installation is done in release mode, hence the code didn't go out in error before).